1. Field of the Invention
This invention relates to friction joints, and more particularly to friction joints wherein there is selective relative movement between a joint member and the joint's housing.
2. Description of the Prior Art
Variable position joints in which the joint member of the joint may be selectively moved with respect to the joints' housing are generally well-known. U.S. Pat. No. 193,235, granted July 10, 1962, to McNew, discloses a joint comprising a yoke-like member which straddles the end of a shaft. A transverse pin, carried by the ends of the yoke, connects the yoke to said shaft with a relatively snug friction fit. However, such a joint permits only one degree of freedom of motion about said transverse pin.
U.S. Pat. No. 2,828,758, granted Apr. 1, 1958, to Moro, discloses a joint 2 which comprises two metal plates 23, 24 between which is sandwiched a rubber disk 25. A pivot 21' holds these elements in association, and when wing nut 22 is tightened on pivot 21', element 23 is held in a fixed angular relation with respect to element 24 by frictional engagement of elements 23, 24 with the rubber disk 25. As is seen, this friction joint is capable of permitting only rotation of element 23 with respect to element 24 about pivot 21'. Clearly this joint is not assembled and disassembled merely by pushing together and pulling apart its various components without the use of tools as in applicant's joint.
Various other forms of shading apparatus are disclosed by U.S. Pat. No. 2,905,187 granted Sept. 22, 1959, to Croce, and U.S. Pat. No. 193,235 granted July 10, 1962, to McNew; 197,055 granted Dec. 10, 1963, to Anderson; 214,226 granted May 20, 1969, to Sewell et al; and 220,991 granted June 22, 1971, to Riley.